Sewing machine



Oct. 2, 19.45, H. E. ALTHENS 2,385,768

I SEWING MACHINE Filed Dec. 24, 1943 :s sheets-sheet 1 l' l .l l Q i I Ll w Z/ rtl-JL I '/,1 V l /7/ Y f6 zg a HWI l I r' :l

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SEWING MACHINE v Oct. 2, 1945.

F-led Dec. 24, 1945 3 Sheets-Sheet 2 oct. 2; 1945.

H. E. AL'rHENs l SEWING MACHINE Filed Deo; 24, 1943 1g @im 3Sheets-Sheet k25 Patented oei. 2, 1945 UNITED STATES PATENT orricaassassinsA SEWING MACHINE nei-bert' a. molens, Newton, Mm., mignon :o'The Reece Brittonl Hole Machine Company, Boston, Mass., a corporationof Maine Application December 24, 1943, Serial No. 515,538 4`Claims.(Cl. 11B-219) 'wol-k, together with power control or stop mechanismwhich is separately manually operated (as by a-second treadle) to startthe machine and automatically operated to stop the machine upon thecompletion of a predetermined sewing oper-- ation. However, theinvention is equally applicable, at least in part, to other types ofsewing machines having separately operated work clamp releasing andstarting and stopping devices.

In machines of this general type, it is highly desirable (in order toavoid injury to the needle the work until after the needle has withdrawnfrom the work in the completion of the last stitchl forming cycle. Theinvention also has for an object vthe provision of an improved andsimplified interlock for this purpose. .l

The foregoing and other objects of the invention, together with meanswhereby the latter may be carried vinto effect, will best beY understoodfrom the following description fof an illustrative embodiment thereofshown in the accompanying drawings, this, however, having been -chosenforv purposes of exempliiication merely, as it is contemplated that the.invention, as defined by the claims hereunto appended, may be otherwiseembodied without departure from itsI spirit and SCOPE.

or the work or both) that the operator be prevented from releasing orlifting the work clamping devices except when the machine is at rest, orabout to stop, and with the needle free from the work, and also beprevented from starting the machine unless the work is properly clamped.

Various expedients, in the nature of interlocks between the manuallyoperated work clamping and releasing and starting and stopping devices,designed to accomplish these results, have been proposed, but so far asI am aware none of these have been such as to prevent manual release orlifting of the work clamp during the final stitchformingv cycle of thesewing operation. In all machines of which I am aware, to which suchprior expedients have been applied, the power control or stop mechanismis of such a character,

and must be so timed, as to movel into stopping position just after thebeginning of the final stitch-forming cycle, during which the needledescends to penetrate the work and thereafter Withdraws therefrom.Consequently, should the operator attempt to anticipate the stopping ofthe machine, by pressing upon the work clamp re- In said drawings: v g jFig. 1 is a side elevation, partly broken away and partly inlongitudinal section, of a'button sewing machine including an embodimentof the invention, some parts of themachine not pertinent to theinvention and not necessary to a full understanding thereof beingomitted.

Fig. 2 is a horizontal section taken substantially on the line 2-2, Fig.1.

Fig. 3 is a fragmentary horizontal section taken substantially on theline 3-3, Fig. 1.

Fig. 4 isa fragmentary vertical section taken substantially on the linel-l, Fig. 2.

Fig. 5 is a view, similar to Fig. 4, showing cer.-

' tain of the parts of the latter figure in a different position.

Fig. 6 is a fragmentary side elevation of parts of the interlockingmechanism shown in Ijig. 1, showing said parts in a different position.

Fig. 7 is a detail view of one member of the v interlocking mechanism.

Figs. 8, 9, y10 and 11 are diagrammatic` viewsy illustratingv theoperation.

The invention is herein illustrated as embodied in a button sewingmachine similar to that described in the aforesaid Reece patent to whichreference may be had for a more complete show- 45 ing of parts not fullyshown and described herein.

leasing treadle prior to the completion of the l sewing operation (asfrequently occurs), the interlock would be released and the work clamplifted when the needle was' descending or was engaged with the work. Thepresent invention has for an object to provide a power control mechanismwhich is so constructed and timed,

0 supported therefrom by an upright housing porand is so inter-relatedor interlocked with the clamp releasing devices as to prevent release ofReferring to Fig. 1, the frame or casing of the machine, which enclosestheprincipal parts of the operating and controlling devices, comprises abase or bed 29 and an overhanging head 2i tion 22. The bed 20 carries awork plate 23 upon which is supported the work W to which a button B isto be attached and against which said work.

is clamped during the sewing operation by a presser-foot 24 associatedwith a buttonv clamp suitably positioned recesses in the wall of thecasm ing 28, 29, said main cam is rotated in definite time relation, andat a reduced speed, with respect to the needle shaft. The main cam makesone complete rotation during a plurality but predetermined number ofcomplete rotations of the needle` shaft, each corresponding to a g. Theshaft 21 of the'main cam 00 being connected with the lneedle shaft 25 bythe worm gear-l stitch-forming cycle during which the needle descends topenetrate the work and thereafter rises therefrom. Consequently, thereis a definite portion lof the angular movement of the main camcorresponding to each stitch-forming cycle, and the stud 04 is sopositioned, with respect to the portion of angular movement (indicatedat a in Fig. 3) corresponding to thenal stitch-form.- ing cycle of thecomplete predetermined sewing operation, as to engage and operate thebunter 52 just prior to the completion of said final stitchformingcycle. Also, the dog 55 is so angularly positioned on the hub 1|, andconsequently on the shaft 25, with respect to the angular- 4positioningof the crank 30 (or equivalent needle bar actuating means) on saidshaft,.that the stop finger 14 approaches the plane of movement of thehead 15 of the stop arm 11 (as shown in Fig. 4), and engages said headto stop the machine (as shown in Fig. 5), if the stop arm is in stoppingposition, just prior to the completion of each stitch-forming cycle andafter the needle has risen or been withdrawn from the work.

The relative timing of the parts is diagrammatically illustrated inFigs. 8 to 1,1. In Fig. 8, the final stitch-forming cycle has been alittle lmore than half completed; the needle 35 is in the work W, hasreached its lowermost position,

and has started to rise therefrom; the stud 04 has not yet engaged thebunter 02', so that the stop larm 1l is still in running position withits head 15 out-of the path of movement of the stop finger 14; and thedog 00 is engaged with the shoulder I, thereby coupling the pulley 25 tothe needle shaft 25. In Fig. 9, the needle has risen far enough todisengage or be withdrawn from the work but is still in proximitythereto, the stud 84 has been brought into engagement with the inclinedend 93 of the bunter but has not yet moved the latter, so that the stoparm is still in running position and the pulley 25 remains coupled tothe needle shaft. In Fig. 10, the needle, now completely withdr-awn fromthe work, is approaching its uppermost position, the stud 04 vhas movedthe bunter 02 far enough to swing the stop arm 11 into stopping positionwith its head 15 in the path of movement of the stop finger 14 which hasreached an angular position where it is about to engage said head. InFig. 11, the needle has reached its uppermost position remote from thework, and the stop finger 14 has engaged the head of the .Stop arm,thereby disengaging the dog 69 from the shoulder 50, uncoupling thepulley 26 from the Vneedle shaft and positively stopping the latter. Itwill therefore be seen that the stop arm (together with the rock shaft04 and arm remains in running position until the needle has beencompletely withdrawn from the work at substantially the completion ofthe final stitch-forming cycle, and that when the stop arm is then movedinto. stopping position the machine is almost immediately stopped withthe needle still remote from the work.

In order to .prevent lifting of the presser-foot 24, -by the treadle, torelease the work, except when the machine is at rest, or is about tostop, with the needle disengaged from the work, and to prevent movementof the stop arm. 'l1 into running position, by the treadle 01, to startthe machine, except when the work is properly clamped to the work plateby the presser-foot, the interlock mechanism best shown in Figs. 1, 2, 6and 'l is provided. The latch lever 52, whosepivot is directly below thefree end of the operating arm 05 to which the link 88 is attached, is inthe form of a bell crank lever having, in addition to the arm 5 3, asecond arm |0| which extends upwardly toward the arm 05. The arm |0| isformed with an-upper arcuate edge portion |02 concentric with the axisof the pivot 59 and underlying a pin |03 extending laterally from thearm 05, said edge. portion terminating in a notch |04 adapted to receivesaid pin. Turning of the lever 52 on its pivot 50 in a counter-clockwisedirection, under the influence of the springs 40 and 50, is limited byengagement of the arm |0| with a pin |05 projecting from the casingwall, and when said arm is in engagement with said pin the notch |04 isdirectly opposite the pin |03. Otherwise, the arcuate edge portion |02is of sumcient length to underlie the pin |03 throughout the range oflifting movement of the presser-foot by the treadle 50.

When the machine is at rest, with the stop arm 11 and operating arm 05in the stopping position shown in broken lines in Fig. l, the pin |03 isfree from the notch 04, and the presserfoot 24 can be lifted bydepression of the treadle 50. When this is done, the arcuate edge |02 ofthe arm |0| of the latch lever 52 passes under the pin |00, as shown inFig. 6, thereby blocking downward movement of the arm 85. Consequently,so long as the presser-foot remains lifted, and thework is unclamped,the arm `85 cannot be operated by the treadle 01 to move the stop arm`11 into running position, shown in full lines in Fig. 1. When thetreadle 50 is released, permitting the spring 40 to restore thepresserfoot to work-clamping position,l the latch lever 52 moves intothe position shown in Fig, 1, carrying the arcuate edge |02 out ofblocking relation to the pin |03 and bringing the notch |04 oppositesaid pin. The treadle 81 can then be4 freely depressed to move the stoparm into running position,`shown in full lines in Fig. 1, to start themachine. When this is done,`the pin |03 enters the notch |04, therebylocking the lever 52 against. clockwise-movement and preventing deuntilit is moved into stopping position, shown in pression ofthe treadle 58to lift the presser-foot and release the work. This condition exists solong as the stop arm is in running position and broken lines in Fig. 1,to stop the machine. As above explained, thisdoes not occur 'until thefinal stitch-forming cycle has been nearly completed and the needlefully'retracted from the stopped, so that the needle cannot againdescend into engagement with the work.

' I claim:

1. In a sewing machine having work clamping means, in combination|manually operated means for starting said machine, other manuallyoperated means for releasing said clamping means,

and means for preventing the concurrent operation oi said manuallyoperated means comprising a pivotally mounted latch having a notched armadapted to prevent the operation of said starting means except when saidnotch is in position to receive an element of said starting means andhaving a lever arm connected with an element of said clamp releasingmeans, said arms having a relative position such that any movement ofsaid lever arm in response to actuation by said releasing means servesto move said notched arm into a position in which said notch is thrownout of receiving position. y

2. In a sewing machine having work clamping means, in combination,manually operated means for starting said machine, other manuallyoperated means for releasing said clamping means, and means forpreventing the concurrent operation of said manually operated meanscomprising a pivotally mounted latch having a notched arm associatedwith said starting means and a lever arm connected to an element of saidreleasing means, said notched arm being adaptedto prevent said startingmeans fromassuming 'starting position except when an element thereof isin line with said notch, the reception of said element into said notchacting to lock said latch against pivotal movement and thereby toprevent operation of said releasing means while said starting meansjisin operation. I

`3. In a sewing machine having work clamping means, in combination,manually operated means ior starting said machine, other manuallyoperated means for releasing said clamping means, and means forpreventing the concurrent operation of said manually operated meanscomprising a pivotally mounted latch having one arm with an arcuate edgeconcentric with the axis ot said -latch adapted to maintain a. constantpredetermined distance between said axis and an element associated withsaid starting means, a notch formed in said edge adapted to receive saidelement so as to permitsaidstarting means to assume startingpositiornand a second armI connecd to an element of said releasing meansadapted on the operation oi' said means to turn said latch to move saidnotch out of receiving po sition and to move said arcuate edge into aposition opposite the element associated with the starting means so thatsaid starting means is locked ini inoperative position during theoperation of saidreleasing means.

4. In a sewing machine having work clamping means, in combination,manually operated means tor starting said machine, other manuallyoperated means for .releasing the clamping means, and means forpreventing the concurrent operation of both manually operated meanscomprising a pivotally mounted latch having one arm with an arcuate edgeconcentric with the axis of the latch adapted to maintain a constantpredetermined distance between the axis and an element associated withthe starting means, a notch formed in said edge adapted to receive saidelement when the starting means is in starting position, and a secondarm connected to a member oi' the releasing means, the reception ci' theelement of said starting means into the notch acting to lock the latchagainst pivotal movement so that the second arm connected to an element

